THE LTSINS. 141 



obtained by immunization becomes inactive when kept for a few 

 hours in the peritoneal cavity ; but in this case, regeneration was 

 accomplished by the addition of fresh serum containing a comple- 

 ment. In these experiments rabbits were treated intravenously with 

 guinea-pig's blood and after a serum had been obtained which had a 

 marked hemolytic action on the blood corpuscles of the guinea-pig 

 some of it was introduced into the peritoneal cavity of a normal 

 rabbit, left there for three hours, and then recovered. " Such peri- 

 toneal serum, when added to guinea-pig's blood, agglutinated it, but 

 caused no hemolysis whatsoever. Addition of immunized rabbit 

 serum, made inactive by heating, to peritoneal serum, had no regen- 

 erating effect. But addition of fresh normal rabbit serum to the im- 

 munized peritoneal serum regenerated it completely ; the mixture of 

 both sera dissolved guinea-pig's blood as readily as the active im- 

 munized serum alone." 



In his studies of cobra lysin, Myers ^ found that when this toxin 

 is treated with anti-venomous serum it behaves similarly to the bac- 

 terial toxins. For instance, it was ascertained that, in order to neu- 

 tralize 1 mg. of cobra poison so that it would no longer manifest a 

 hemolytic action on the blood corpuscles of man, 1.3 c.c. of anti- 

 venomous serum was required; but when 0.1 c.c. of the serum was 

 added to 1 mg. of the venom, it deprived it of four-fifths of its toxic 

 action, and when 0.2 c.c. of the serum was used it destroyed nine- 

 tenths of the hemolytic power of the venom. If these figures be 

 compared with those given by Madsen in his studies of tetanolysin 

 and already referred to on page 64, the similarity will be evident. 

 Myers found that the hemolytic action of a sample of dry venom re- 

 mains constant for a long time, but such a venom in dilute solution 

 rapidly decreases in hemolytic action until it reaches a minimum, 

 when there is no further change. This is evidence that bodies simi- 

 lar to the toxoids described by Ehrlich are also formed in cobra 

 lysin. 



Bulloch and Hunter^ have shown that filtered cultures of the ba- 

 cillus pyocyaneus dissolve the red corpuscles of the ox, the sheep, 

 rabbit, monkey, cat, dog and rat. The more concentrated the solu- 

 tion of the toxin the more rapidly does its hemolytic action manifest 

 itself, but in all the experiments there appeared to be a latent period 

 during which there was no hemolysis. A goat was immunized with 

 filtrates of this bacillus, and in the serum of this animal there ap- 

 peared an anti-hemolytic substance which manifested its neutralizing 

 effects in vitro. In experimenting with this substance it was ob- 

 served that while small quantities of the immune serum did not pre- 

 vent hemolysis and medium quantities did, excessively large amounts 

 of the serum led to renewed hemolytic action. 



' TransaetUms of the Pathologieal Society of London, 51. 

 * Ibidem. 



